A vegan man in the USA is suing Burger King for allegedly misleading him to believe that the Impossible Whopper was vegan.

Phillip Williams of Georgia said that the fast-food chain did not advertise adequately that the Impossible Whopper, a plant-based Whopper alternative, needed to be specifically asked to be cooked differently for it to be vegan. Williams was aware that there was non-vegan mayonnaise in the burger but didn’t know that the patty was in fact cooked with beef fat on the same grill as the other meats.

Burger King has since said that they never advertise the Impossible Whopper specifically for vegans and in fact, the burger’s target audience is flexitarians.

The lawsuit is seeking a jury trial, compensatory damages and an injunction to stop Burger King from cooking the patties on a cross-contaminated grill.